A NEW TYPE OF PUZZLE discovered in the ancient Mayan Pyramids of México, it is a puzzle using only numbers. We bring you the 7 X 7 version. There are 165 puzzles and solutions in this Volume 131. This volume is for the more advanced player of the game. Learn what the Mayans knew long ago about teaching the brain to develop a quick positive response. This set of puzzle games will help to put math in a positive light for any age group. It will teach you Problem Solving. It helps in the following areas: Memory, Attention, Focus, Speed, Visual Perception, Spatial Reasoning, Managing Stress, and Rapid Reaction Time, (RRT). TUNE UP YOUR BRAIN, TODAY! We also have these books as apps at this link, click here.